Is there a pressure switch in system to turn on brake lights or is the switch on the brake pedal the only thing that triggers lights?

 

Just the brake light switch operated by pressing the pedal.

 

What vehicle is it. It depends on the vehicle - '73 and newer uses a electric switch on the brake pedal arm, the older ones have a switch in the brake lines that's activated by brake fluid pressure.

Both types of switches should have two wires with one being hot always and both hot with pedal pushed down. Get a test light or volt meter and check for power.

Marty

 

There are two switches.
Upper is a vacuum operated switch, lower switch attached at pivot point of pedal arm.

I have checked both switches and found nothing wrong....Maybe I am not doing something right.

Could somebody explain the operation of these components.